1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LEDs driver for GPIOs 4 * 5 * Copyright (C) 2007 8D Technologies inc. 6 * Raphael Assenat <raph@8d.com> 7 * Copyright (C) 2008 Freescale Semiconductor, Inc. 8 */ 9 #include <linux/container_of.h> 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/gpio.h> 13 #include <linux/gpio/consumer.h> 14 #include <linux/leds.h> 15 #include <linux/mod_devicetable.h> 16 #include <linux/module.h> 17 #include <linux/overflow.h> 18 #include <linux/pinctrl/consumer.h> 19 #include <linux/platform_device.h> 20 #include <linux/property.h> 21 #include <linux/slab.h> 22 #include <linux/types.h> 23 24 #include "leds.h" 25 26 struct gpio_led_data { 27 struct led_classdev cdev; 28 struct gpio_desc *gpiod; 29 u8 can_sleep; 30 u8 blinking; 31 gpio_blink_set_t platform_gpio_blink_set; 32 }; 33 34 static inline struct gpio_led_data * 35 cdev_to_gpio_led_data(struct led_classdev *led_cdev) 36 { 37 return container_of(led_cdev, struct gpio_led_data, cdev); 38 } 39 40 static void gpio_led_set(struct led_classdev *led_cdev, 41 enum led_brightness value) 42 { 43 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 44 int level; 45 46 if (value == LED_OFF) 47 level = 0; 48 else 49 level = 1; 50 51 if (led_dat->blinking) { 52 led_dat->platform_gpio_blink_set(led_dat->gpiod, level, 53 NULL, NULL); 54 led_dat->blinking = 0; 55 } else { 56 if (led_dat->can_sleep) 57 gpiod_set_value_cansleep(led_dat->gpiod, level); 58 else 59 gpiod_set_value(led_dat->gpiod, level); 60 } 61 } 62 63 static int gpio_led_set_blocking(struct led_classdev *led_cdev, 64 enum led_brightness value) 65 { 66 gpio_led_set(led_cdev, value); 67 return 0; 68 } 69 70 static int gpio_blink_set(struct led_classdev *led_cdev, 71 unsigned long *delay_on, unsigned long *delay_off) 72 { 73 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 74 75 led_dat->blinking = 1; 76 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, 77 delay_on, delay_off); 78 } 79 80 static int create_gpio_led(const struct gpio_led *template, 81 struct gpio_led_data *led_dat, struct device *parent, 82 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set) 83 { 84 struct led_init_data init_data = {}; 85 struct pinctrl *pinctrl; 86 int ret, state; 87 88 led_dat->cdev.default_trigger = template->default_trigger; 89 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); 90 if (!led_dat->can_sleep) 91 led_dat->cdev.brightness_set = gpio_led_set; 92 else 93 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; 94 led_dat->blinking = 0; 95 if (blink_set) { 96 led_dat->platform_gpio_blink_set = blink_set; 97 led_dat->cdev.blink_set = gpio_blink_set; 98 } 99 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) { 100 state = gpiod_get_value_cansleep(led_dat->gpiod); 101 if (state < 0) 102 return state; 103 } else { 104 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 105 } 106 led_dat->cdev.brightness = state; 107 led_dat->cdev.max_brightness = 1; 108 if (!template->retain_state_suspended) 109 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 110 if (template->panic_indicator) 111 led_dat->cdev.flags |= LED_PANIC_INDICATOR; 112 if (template->retain_state_shutdown) 113 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; 114 115 ret = gpiod_direction_output(led_dat->gpiod, state); 116 if (ret < 0) 117 return ret; 118 119 if (template->name) { 120 led_dat->cdev.name = template->name; 121 ret = devm_led_classdev_register(parent, &led_dat->cdev); 122 } else { 123 init_data.fwnode = fwnode; 124 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, 125 &init_data); 126 } 127 128 if (ret) 129 return ret; 130 131 pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev); 132 ret = PTR_ERR_OR_ZERO(pinctrl); 133 /* pinctrl-%d not present, not an error */ 134 if (ret == -ENODEV) 135 ret = 0; 136 if (ret) { 137 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n", 138 fwnode, ret); 139 } 140 141 return ret; 142 } 143 144 struct gpio_leds_priv { 145 int num_leds; 146 struct gpio_led_data leds[] __counted_by(num_leds); 147 }; 148 149 static struct gpio_leds_priv *gpio_leds_create(struct device *dev) 150 { 151 struct fwnode_handle *child; 152 struct gpio_leds_priv *priv; 153 int count, ret; 154 155 count = device_get_child_node_count(dev); 156 if (!count) 157 return ERR_PTR(-ENODEV); 158 159 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); 160 if (!priv) 161 return ERR_PTR(-ENOMEM); 162 163 device_for_each_child_node(dev, child) { 164 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds]; 165 struct gpio_led led = {}; 166 167 /* 168 * Acquire gpiod from DT with uninitialized label, which 169 * will be updated after LED class device is registered, 170 * Only then the final LED name is known. 171 */ 172 led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS, 173 NULL); 174 if (IS_ERR(led.gpiod)) { 175 dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n", 176 child); 177 fwnode_handle_put(child); 178 return ERR_CAST(led.gpiod); 179 } 180 181 led_dat->gpiod = led.gpiod; 182 183 led.default_state = led_init_default_state_get(child); 184 185 if (fwnode_property_present(child, "retain-state-suspended")) 186 led.retain_state_suspended = 1; 187 if (fwnode_property_present(child, "retain-state-shutdown")) 188 led.retain_state_shutdown = 1; 189 if (fwnode_property_present(child, "panic-indicator")) 190 led.panic_indicator = 1; 191 192 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 193 if (ret < 0) { 194 fwnode_handle_put(child); 195 return ERR_PTR(ret); 196 } 197 /* Set gpiod label to match the corresponding LED name. */ 198 gpiod_set_consumer_name(led_dat->gpiod, 199 led_dat->cdev.dev->kobj.name); 200 priv->num_leds++; 201 } 202 203 return priv; 204 } 205 206 static const struct of_device_id of_gpio_leds_match[] = { 207 { .compatible = "gpio-leds", }, 208 {}, 209 }; 210 211 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 212 213 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 214 const struct gpio_led *template) 215 { 216 struct gpio_desc *gpiod; 217 unsigned long flags = GPIOF_OUT_INIT_LOW; 218 int ret; 219 220 /* 221 * This means the LED does not come from the device tree 222 * or ACPI, so let's try just getting it by index from the 223 * device, this will hit the board file, if any and get 224 * the GPIO from there. 225 */ 226 gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW); 227 if (IS_ERR(gpiod)) 228 return gpiod; 229 if (gpiod) { 230 gpiod_set_consumer_name(gpiod, template->name); 231 return gpiod; 232 } 233 234 /* 235 * This is the legacy code path for platform code that 236 * still uses GPIO numbers. Ultimately we would like to get 237 * rid of this block completely. 238 */ 239 240 /* skip leds that aren't available */ 241 if (!gpio_is_valid(template->gpio)) 242 return ERR_PTR(-ENOENT); 243 244 if (template->active_low) 245 flags |= GPIOF_ACTIVE_LOW; 246 247 ret = devm_gpio_request_one(dev, template->gpio, flags, 248 template->name); 249 if (ret < 0) 250 return ERR_PTR(ret); 251 252 gpiod = gpio_to_desc(template->gpio); 253 if (!gpiod) 254 return ERR_PTR(-EINVAL); 255 256 return gpiod; 257 } 258 259 static int gpio_led_probe(struct platform_device *pdev) 260 { 261 struct device *dev = &pdev->dev; 262 struct gpio_led_platform_data *pdata = dev_get_platdata(dev); 263 struct gpio_leds_priv *priv; 264 int i, ret; 265 266 if (pdata && pdata->num_leds) { 267 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL); 268 if (!priv) 269 return -ENOMEM; 270 271 priv->num_leds = pdata->num_leds; 272 for (i = 0; i < priv->num_leds; i++) { 273 const struct gpio_led *template = &pdata->leds[i]; 274 struct gpio_led_data *led_dat = &priv->leds[i]; 275 276 if (template->gpiod) 277 led_dat->gpiod = template->gpiod; 278 else 279 led_dat->gpiod = 280 gpio_led_get_gpiod(dev, i, template); 281 if (IS_ERR(led_dat->gpiod)) { 282 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n", 283 template->gpio, template->name); 284 continue; 285 } 286 287 ret = create_gpio_led(template, led_dat, dev, NULL, 288 pdata->gpio_blink_set); 289 if (ret < 0) 290 return ret; 291 } 292 } else { 293 priv = gpio_leds_create(dev); 294 if (IS_ERR(priv)) 295 return PTR_ERR(priv); 296 } 297 298 platform_set_drvdata(pdev, priv); 299 300 return 0; 301 } 302 303 static void gpio_led_shutdown(struct platform_device *pdev) 304 { 305 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 306 int i; 307 308 for (i = 0; i < priv->num_leds; i++) { 309 struct gpio_led_data *led = &priv->leds[i]; 310 311 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 312 gpio_led_set(&led->cdev, LED_OFF); 313 } 314 } 315 316 static struct platform_driver gpio_led_driver = { 317 .probe = gpio_led_probe, 318 .shutdown = gpio_led_shutdown, 319 .driver = { 320 .name = "leds-gpio", 321 .of_match_table = of_gpio_leds_match, 322 }, 323 }; 324 325 module_platform_driver(gpio_led_driver); 326 327 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 328 MODULE_DESCRIPTION("GPIO LED driver"); 329 MODULE_LICENSE("GPL"); 330 MODULE_ALIAS("platform:leds-gpio"); 331